| File: | src/sbin/dmesg/dmesg.c |
| Warning: | line 90, column 2 Value stored to 'argv' is never read |
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| 1 | /* $OpenBSD: dmesg.c,v 1.31 2019/12/24 13:20:44 bluhm Exp $ */ |
| 2 | /* $NetBSD: dmesg.c,v 1.8 1995/03/18 14:54:49 cgd Exp $ */ |
| 3 | |
| 4 | /*- |
| 5 | * Copyright (c) 1991, 1993 |
| 6 | * The Regents of the University of California. All rights reserved. |
| 7 | * |
| 8 | * Redistribution and use in source and binary forms, with or without |
| 9 | * modification, are permitted provided that the following conditions |
| 10 | * are met: |
| 11 | * 1. Redistributions of source code must retain the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer. |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in the |
| 15 | * documentation and/or other materials provided with the distribution. |
| 16 | * 3. Neither the name of the University nor the names of its contributors |
| 17 | * may be used to endorse or promote products derived from this software |
| 18 | * without specific prior written permission. |
| 19 | * |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 21 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 22 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 23 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 24 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 25 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 26 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 27 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 28 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 29 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 30 | * SUCH DAMAGE. |
| 31 | */ |
| 32 | |
| 33 | #include <sys/types.h> |
| 34 | #include <sys/msgbuf.h> |
| 35 | #include <sys/sysctl.h> |
| 36 | |
| 37 | #include <err.h> |
| 38 | #include <fcntl.h> |
| 39 | #include <kvm.h> |
| 40 | #include <limits.h> |
| 41 | #include <nlist.h> |
| 42 | #include <stddef.h> |
| 43 | #include <stdio.h> |
| 44 | #include <stdlib.h> |
| 45 | #include <string.h> |
| 46 | #include <unistd.h> |
| 47 | #include <vis.h> |
| 48 | |
| 49 | #ifndef NOKVM |
| 50 | struct nlist nl[] = { |
| 51 | #define X_MSGBUF0 0 |
| 52 | { "_msgbufp" }, |
| 53 | { NULL((void*)0) }, |
| 54 | }; |
| 55 | #endif |
| 56 | |
| 57 | void usage(void); |
| 58 | |
| 59 | #define KREAD(addr, var)kvm_read(kd, addr, &var, sizeof(var)) != sizeof(var) \ |
| 60 | kvm_read(kd, addr, &var, sizeof(var)) != sizeof(var) |
| 61 | |
| 62 | int |
| 63 | main(int argc, char *argv[]) |
| 64 | { |
| 65 | int ch, newl, skip, i; |
| 66 | char *p; |
| 67 | struct msgbuf cur; |
| 68 | char *memf, *nlistf, *bufdata = NULL((void*)0); |
| 69 | char *allocated = NULL((void*)0); |
| 70 | int startupmsgs = 0; |
| 71 | char buf[5]; |
| 72 | |
| 73 | memf = nlistf = NULL((void*)0); |
| 74 | while ((ch = getopt(argc, argv, "sM:N:")) != -1) |
| 75 | switch(ch) { |
| 76 | case 's': |
| 77 | startupmsgs = 1; |
| 78 | break; |
| 79 | case 'M': |
| 80 | memf = optarg; |
| 81 | break; |
| 82 | case 'N': |
| 83 | nlistf = optarg; |
| 84 | break; |
| 85 | case '?': |
| 86 | default: |
| 87 | usage(); |
| 88 | } |
| 89 | argc -= optind; |
| 90 | argv += optind; |
Value stored to 'argv' is never read | |
| 91 | |
| 92 | if (memf == NULL((void*)0) && nlistf == NULL((void*)0)) { |
| 93 | int mib[2], msgbufsize; |
| 94 | size_t len; |
| 95 | |
| 96 | mib[0] = CTL_KERN1; |
| 97 | mib[1] = startupmsgs ? KERN_CONSBUFSIZE82 : KERN_MSGBUFSIZE38; |
| 98 | len = sizeof(msgbufsize); |
| 99 | if (sysctl(mib, 2, &msgbufsize, &len, NULL((void*)0), 0)) |
| 100 | err(1, "sysctl: %s", startupmsgs ? "KERN_CONSBUFSIZE" : |
| 101 | "KERN_MSGBUFSIZE"); |
| 102 | |
| 103 | msgbufsize += offsetof(struct msgbuf, msg_bufc)__builtin_offsetof(struct msgbuf, msg_bufc); |
| 104 | allocated = bufdata = calloc(1, msgbufsize); |
| 105 | if (bufdata == NULL((void*)0)) |
| 106 | errx(1, "couldn't allocate space for buffer data"); |
| 107 | |
| 108 | mib[1] = startupmsgs ? KERN_CONSBUF83 : KERN_MSGBUF48; |
| 109 | len = msgbufsize; |
| 110 | if (sysctl(mib, 2, bufdata, &len, NULL((void*)0), 0)) |
| 111 | err(1, "sysctl: %s", |
| 112 | startupmsgs ? "KERN_CONSBUF" : "KERN_MSGBUF"); |
| 113 | |
| 114 | if (pledge("stdio", NULL((void*)0)) == -1) |
| 115 | err(1, "pledge"); |
| 116 | |
| 117 | memcpy(&cur, bufdata, sizeof(cur)); |
| 118 | bufdata = ((struct msgbuf *)bufdata)->msg_bufc; |
| 119 | } else { |
| 120 | #ifndef NOKVM |
| 121 | struct msgbuf *bufp; |
| 122 | kvm_t *kd; |
| 123 | |
| 124 | /* Read in kernel message buffer, do sanity checks. */ |
| 125 | if ((kd = kvm_open(nlistf, memf, NULL((void*)0), O_RDONLY0x0000, |
| 126 | "dmesg")) == NULL((void*)0)) |
| 127 | return (1); |
| 128 | |
| 129 | if (pledge("stdio", NULL((void*)0)) == -1) |
| 130 | err(1, "pledge"); |
| 131 | |
| 132 | if (kvm_nlist(kd, nl) == -1) |
| 133 | errx(1, "kvm_nlist: %s", kvm_geterr(kd)); |
| 134 | if (nl[X_MSGBUF0].n_type == 0) |
| 135 | errx(1, "%s: msgbufp not found", |
| 136 | nlistf ? nlistf : "namelist"); |
| 137 | if (KREAD(nl[X_MSGBUF].n_value, bufp)kvm_read(kd, nl[0].n_value, &bufp, sizeof(bufp)) != sizeof (bufp)) |
| 138 | errx(1, "kvm_read: %s: (0x%lx)", kvm_geterr(kd), |
| 139 | nl[X_MSGBUF0].n_value); |
| 140 | if (KREAD((long)bufp, cur)kvm_read(kd, (long)bufp, &cur, sizeof(cur)) != sizeof(cur )) |
| 141 | errx(1, "kvm_read: %s (%0lx)", kvm_geterr(kd), |
| 142 | (unsigned long)bufp); |
| 143 | if (cur.msg_magic != MSG_MAGIC0x063061) |
| 144 | errx(1, "magic number incorrect"); |
| 145 | allocated = bufdata = malloc(cur.msg_bufs); |
| 146 | if (bufdata == NULL((void*)0)) |
| 147 | errx(1, "couldn't allocate space for buffer data"); |
| 148 | if (kvm_read(kd, (long)&bufp->msg_bufc, bufdata, |
| 149 | cur.msg_bufs) != cur.msg_bufs) |
| 150 | errx(1, "kvm_read: %s", kvm_geterr(kd)); |
| 151 | kvm_close(kd); |
| 152 | #endif |
| 153 | } |
| 154 | |
| 155 | if (cur.msg_bufx >= cur.msg_bufs) |
| 156 | cur.msg_bufx = 0; |
| 157 | /* |
| 158 | * The message buffer is circular; start at the read pointer, and |
| 159 | * go to the write pointer - 1. |
| 160 | */ |
| 161 | for (newl = skip = i = 0, p = bufdata + cur.msg_bufx; |
| 162 | i < cur.msg_bufs; i++, p++) { |
| 163 | if (p == bufdata + cur.msg_bufs) |
| 164 | p = bufdata; |
| 165 | ch = *p; |
| 166 | /* Skip "\n<.*>" syslog sequences. */ |
| 167 | if (skip) { |
| 168 | if (ch == '>') |
| 169 | newl = skip = 0; |
| 170 | continue; |
| 171 | } |
| 172 | if (newl && ch == '<') { |
| 173 | skip = 1; |
| 174 | continue; |
| 175 | } |
| 176 | if (ch == '\0') |
| 177 | continue; |
| 178 | newl = ch == '\n'; |
| 179 | vis(buf, ch, 0, 0); |
| 180 | if (buf[1] == 0) |
| 181 | putchar(buf[0])(!__isthreaded ? __sputc(buf[0], (&__sF[1])) : (putc)(buf [0], (&__sF[1]))); |
| 182 | else |
| 183 | printf("%s", buf); |
| 184 | } |
| 185 | if (!newl) |
| 186 | putchar('\n')(!__isthreaded ? __sputc('\n', (&__sF[1])) : (putc)('\n', (&__sF[1]))); |
| 187 | free(allocated); |
| 188 | return (0); |
| 189 | } |
| 190 | |
| 191 | void |
| 192 | usage(void) |
| 193 | { |
| 194 | extern char *__progname; |
| 195 | |
| 196 | fprintf(stderr(&__sF[2]), "usage: %s [-s] [-M core] [-N system]\n", __progname); |
| 197 | exit(1); |
| 198 | } |